30 x 22 however irc m1305 1 3 regarding the attic passageway access not attic access is not as clear because it uses two different dimensions in relation to the term opening used twice in the same paragraph.
Attic access irc.
Buildings with combustible ceiling or roof construction shall have an attic access.
Irc 807 1 is clear to me with its dimensions for attic access.
Bajnai chesterfield county va icc building code action committee revise as follows.
Habitable attics require a vertical access and emergency escape and rescue opening.
The 2009 and 2015 irc verbiage is similar and still applicable.
Buildings with combustible ceiling or roof construction shall have an attic access opening to attic areas that have a vertical height of 30 inches 762 mm or greater over an area of not less than 30 square feet 2 8 m 2 the vertical height shall be measured from the top of the ceiling framing members to the underside of the roof framing members.
See section m1305 1 3 for access requirements where mechanical equipment is located in attics.
This is applicable to finished and unfinished spaces.
Section r807 attic access r807 1 attic access.
Irc 12 13 section r807 1 proponent.